Dome ports?

So,,,

Domes,,,

What are they and do they do?

Why is it preferred by SLR shooters?

How does it differ from flat ports?

And isn't it more fragile than plat ports?

These questions have been spinning in that brain of mine for quite a while. But I didnt want to ask about it cuz I'm not an SLR shooter and cuz I was hoping that somone else was going to ask those questions. But when a land photographer asked me about domes and found me unable to answer, I said enough is enough. No more waiting and no more ignorance.

So? What's the deal with domes?

I'm all err eyes.

Saad

Domes are only required for wide-angle lenses. Flat ports are used exclusively for other lenses. That's the difference.

Now, to understand why you need a dome port for a wide-angle lens, you need to imagine the angle of view of a wide-angle lens. The wider the anngle, the larger a flat port would need to be to allow the lens to see the entire seen without obscuring part of the picture, around the corners.

For very wide lenses, this would result in extremely large ports. For fisheye lenses, you could actually never get away with a flat port without blocking the corners.

A dome port allows a wide angle lens to see the entire picture, without blocking the corners, in the most efficient shape and size possible.

Cheers,

Mat

And in addition to Matt's explanation, flat ports also change the apparent focal length. Just like everything underwater looks 30% bigger through your mask, the same happens with a flat port. When you're interested in macro you gladly accept the extra magnification but for WA you don't want your field of view to be reduced.

Bart

Well now it makes sense to me.

Thanks Mat.

Thanks Bart.

Cheers,

Saad